This invention relates to display systems and, more particularly, to an efficient system for displaying character and/or graphic information on a color video display.
This invention further relates to copending United States patent applications Ser. Nos. 785,143; 785,144 and 785,145, each being filed on even date with, and assigned to, the assignee of the present invention.
Character generators are utilized to generate character and graphic information to be displayed on a video display device. In general, the video display is organized in the form of a matrix in such a manner that a character, or other graphic pattern, fills each square of the matrix. A display memory is provided which, in prior art systems, receives a character to be displayed from the character generator. The display memory of such system therefore contains the actual information to be displayed, including color. For example, a standard television set includes a display which has a 3:4 aspect ratio and may, therefore, be organized as a 32-horizontal-by-24-vertical matrix. Each square within the matrix is, itself, composed of a matrix such as an 8-by-8 character grid. Thus, in such an exemplary system, the display is capable of displaying 768 characters, or other graphic patterns, with each pattern being resolved on a 64-square grid. Since the character might be in any one of three colors, a memory having on the order of 150K bits is required to store the complete 768 character display.
It is therefore an object of the present invention to provide an improved system for displaying character and other graphic patterns on a color video display.
A further object of the invention is to provide a system for displaying character and other graphic information in color video display with considerable reduction of required memory.